The present invention relates to an improved device and method for detecting the presence of phenothiazine-type drugs in urine. The device comprises a mass of cation exchange resin having in contact therewith a color reactive reagent which when contacted with a solution containing a phenothiazine-type drug cause a color change to occur.
Phenothiazine and related drugs are presently in wide use throughout medicine and psychiatry in connection with the treatment of certain mental disorders. While there action is still incompletely understood, they are of definite benefit in the treatment of a variety of psychiatric disorders. For example, under systematic chemotherapy, psychotic patients whose illness is characterized by catatonic depressive, or paranoid symptomatology may show remission of symptoms and can be discharged into the community. Unfortunately, the same patients who are most benefited by chemotherapy are most likely to omit intake of their prescribed drug. Consequently, in the treatment of such patients, it is important to provide objective evidence of actual drug intake.
This need to determine drug intake is well known in the art and to accomplish such a purpose a number of methods for detecting the presence of phenothiazine-type drugs in the urine were developed. (See Forrest F. M., Forrest I. S. & Mason A. S., Review of Rapid Urine Tests for Phenothiazine and Related Drugs, American Journal Psychiatry vol. 118: pp. 300-307, 1961). However, all of these methods employed chemical systems which required the use of strong liquid mineral acids, generally at a pH of 1.0 or less, in combination with ferric chloride. The low pH is necessary for the specificity of the test. Because of this requirement for a strong acid solution, these previous methods are generally considered not suitable for safe use by untrained persons on an outpatient basis. Accordingly, there was a need for a safe and efficient device and method for detecting the presence of phenothiazine-type drugs in urine.
This problem of unreliable chemotherapy intake by psychiatric patients was solved in part by the use of injectable slow release compounds such as prolixin tri flu perazine deconate. However, the rate of metabolism and/or effective dosage of these agents varies considerably from one patient to the next. Thus, it is difficult to determine on an individual basis when a new injection is required.
Accordingly, it became apparent that there was a need for a safe urine screening test, preferably in dry "dip stick" form, for the presence of psychophramacologic metabolic products of phenothiazine-type drugs.
Therefore, the primary objective of the presence invention is to provide a device and method for determining the presence of phenothiazine-type drugs in urine which does not require the use of a liquid mineral acid.
Another objective of the present invention is to provide a safe sensitive urine screening test for the metabolic products of injectable slow release phenothiazine-type drugs.
A further objective of this invention is to provide a reagent system for producing a permanent color change in the presence of phenothiazine related drugs. (Previous methods have yielded reactions with transient color changes having a critical reading time).
In addition, another object of the invention is to provide a simple, but accurate and safe, device and method which can be used in the emergency room to determine whether a patient is suffering from an overdose of a phenothiazine related drug.
Other objects of the invention will become apparent to those skilled in the art from a reading of the specification and claims.
The improved device and method of the invention provides a more rapid, accurate, and persisting color change in the presence of these psychopharmacologic agents of the phenothiazine-type than previous methods. Furthermore this method is safe for use by persons not possessing a high level of training and skill in clinical chemistry. More specifically, the method does not require the use of strong liquid acids, as do previously described systems. Accordingly, the present invention overcomes certain problems associated with the prior method and techniques used to determine the presence of phenothiazine-type drugs.